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(*NoModl.) I D. H. CHURCH.

MAINSPRING FOR WATCHES.

Elm 295,485. Patented Mar. 18,1884.

UNITED STATES PATENT OFFICE.

DUANE H. CHURCH, OF WALTHAM, MASSACHUSETTS, ASSIGNOR TO THE AMERICAN WATCH COMPANY, OF SAME PLACE.

MAINSPRINIG FOR WATCHES.

SPECIFICATION forming part of Letters Patent No. 295,485, dated March 18, 1884.

Application filed August 29, 1883. (No model.)

To all whom it may concern.-

Be it known that I, DUANE H. CHURCH, of Waltham, in the county of Middlesex and State of Massachusetts, have invented certain Improvements in Mainsprings for Watches, of

which the following is a specification.

This invention relates to the outer end of a watchmainspring at the point where the spring is secured to its barrel. The spring is provided at its outer end with two cars projecting from opposite edges of the spring and entering orifices formed in the plates or sides of the barrel. Heretofore said ears have been formed on a separate plate, which is riveted to the end of the spring.

My invention consists in forming said ears integral with the end of the spring, and there by obviating the expense and'labor of securing another part thereto, as I will no proceed to describe.

Of the accompanying drawings, forming a part of this specification, Figure 1 represents a view showing the first step in the operation of forming the ears on the spring. Fig. 2 mp resents the second step. Fig. 3 represents the end of a spring constructed in the usual way.

The same letters of reference indicate the same parts in all the figures.

In carrying out my invention, I take a mainspring, a, and split its outer end midway between its edges, as shown at b. I bend the two parts or bifurcations thus formed outwardly in opposite directions, the splitting and bending being preferably accomplished at the same time by a pair of dies or rolls of suitable construction. The edges of the spring are thus offset or separated at the end thereof,

so that they project considerably beyond the edges of the body of the spring. Lastly, I trim the outwardly-bent ends, as shown in 40 Fig. 2, by suitable dies, so as to form two ears,

0 c, on the laterally -projecting portions of the metal. By this process the ears 0 c are made integral with the body of the spring, and I avoid the labor and expense of making a separate plate, (I, provided with said ears, and riveting said plate to the spring, as shown in Fig. 3. The spring is secured to its barrel in the usual mannerviz., by inserting the ears 0 c in orifices formed in the sides of the barrel.

It is obvious that the describedirnprovement may be applied to mainsprings for clocks and other kindred mechanism.

I claim 1. The process herein described of forming ears on mainsprings, the same consisting in splitting the end of the spring, bending outwardly the parts of the split end, and trim-" ming said outwardly-bent parts to form cars, as set forth.

2. Amainspringhavinglaterally-projecting ears 0 c integral with the body of the spring, as set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 16th day of August, 1883.

. DUANE H. CHURCH.

W'itnesses:

G. F; BROWN, A. L. WHITE. 

